Cryptology ePrint Archive: Report 2004/323

A note on L\'opez-Dahab coordinates

Tanja Lange

Abstract: L\'opez-Dahab coordinates are usually the system of choice for
implementations of elliptic curves over binary fields. We give new
formulas for doubling which need one squaring less and one more
addition. This leads to a speed-up for binary fields in polynomial
basis representation.